Class VInt8IntEncoder

An IntEncoder which implements variable length encoding. A number is
encoded as follows:

If it is less than 127 and non-negative, i.e. uses only 7 bits, it is
encoded as a single byte: 0bbbbbbb.

If it occupies more than 7 bits, it is represented as a series of bytes,
each byte carrying 7 bits. All but the last byte have the MSB set, the last
one has it unset.

Example:

n = 117 = 01110101: This has less than 8 significant bits, therefore is
encoded as 01110101 = 0x75.

n = 100000 = (binary) 11000011010100000. This has 17 significant bits,
thus needs three Vint8 bytes. Pad it to a multiple of 7 bits, then split it
into chunks of 7 and add an MSB, 0 for the last byte, 1 for the others:
1|0000110 1|0001101 0|0100000 = 0x86 0x8D 0x20.

NOTE: although this encoder is not limited to values ≥ 0, it is not
recommended for use with negative values, as their encoding will result in 5
bytes written to the output stream, rather than 4. For such values, either
use SimpleIntEncoder or write your own version of variable length
encoding, which can better handle negative values.

WARNING: This API is experimental and might change in incompatible ways in the next release.

createMatchingDecoder

Returns an IntDecoder which matches this encoder. Every encoder
must return an IntDecoder and null is not a valid
value. If an encoder is just a filter, it should at least return its
wrapped encoder's matching decoder.

NOTE: this method should create a new instance of the matching
decoder and leave the instance sharing to the caller. Returning the same
instance over and over is risky because encoders and decoders are not
thread safe.